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General Information => General => Topic started by: RabbitJockey on August 31, 2013, 08:35:24 pm
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This is just my theory, but i think it could save everyone many headaches if they are planning on switching to head studs.
So I had a minor head gasket leak on my 81 rabbit with an 11mm 1.6d engine. I bought ARP head studs to use they are Part number: 204-4701, and meant for use on vw 8v gas engines. They were cheapest from LightningMotorsports.com, and they arrived very quickly.
first i got the head sat on and ran all the studs in to hand tightness
then i screwed all the nuts on to the studs by hand using a long extension with a 1/2" 12pt socket, so it was very easy to wind them on, no hang ups or anything weird, just made them hand tight with the extension.
after this, i went to do my planned torque sequence of 35ftlbs-70ftlbs-100ftlbs
35 was very easy, no qualms but i noticed that after i did #2 in the sequence the nuts needed to be spun down a little before they had any kind of tightness for the ratchet to work. so the tightness of the center 2 studs definitely effected the others
70 took a little more effort, and i noticed the same thing, that after the first 2 studs the rest became alot easier,
at 100, the trouble started!!!!!!!!!!!!!!!!!!!!!!!!!! the first stud was difficult how ever not impossible to turn, and i got it up to 100 ft lbs. the second stud how ever would not budge. i'll be honest, i have always been a scrawny guy, but seriously this one would not move, it ended up feeling like i was going to strip the 12pt shape of the nut so i stopped. and i was like well i'll skip that one, and i did 3-4-5-6, then went back to 2, and that nut wouldn't budge, i ended up half stripping off the 12 pt shape. so since that wasn't going well, i removed the nut and stud, the nut was very difficult to get off the stud, and when i looked inside the nut, all the threads were squared off.
My THEORY is that on that #1 stud, when the nut tightens down, it lowers the rear of the head, and this puts leverage on the second nut, since it is directly in front of it and well, i guess the head gasket is the leverage/pivot point, and the #2 stud is the opposite seat on the seee saw. and that leverage is too much for the #2 stud/nut and screws up the threads. This i have concluded after considering how much torquing one stud seems to effect another, how the outside bolts got easier and easier as i went.
So my recommendation, for all you stud wielders, is after 60-70 ft lbs, you should increase torque values in much lower increments, such is 5-10 ftlbs. though it is a problem which will probably only effect 1 in every thousand of us, the extra 20 minutes you spend torquing the nuts slowly, is well worth the time you'd spend trying to get a warranty stud and nut from arp or raceware.
This also happened to crazy andy, on the exact same stud, tho his engine was an aaz.
please take caution when tightening, and save your self the aggravation of a warranty process that i am about to go through.
first off, i would like to apologize for all the broken families and aneurisms that this thread which I have created may have caused.
Secondly, i'd like to let you all know that i deeply care about every single one of you.
The depth to which i care, is exactly why i am about to make a sacrifice, that many would shy away from. Many, simply do not have the balls to do what i am prepared to do for this community, whom i care so much about.
I will proudly wear egg on my face for you, vwdiesel.net.
the problem was my very own fault, as the nut tightens over the stud, the stud begins to stick up, i measured them at .240" above the nut at full tightness, and if you are not using a socket that is deep enough then obviously at some point its going to slip. this is why like i said on the stud i had a major issue with, i couldn't tighten it with out it feeling like it was going to strip. I failed to notice this is what was going on until today when i was retorque after warmup. i realize its been about a month and a half since i initially posted this, but between making time to work on it, and a few other problems i had, plus waiting on parts and stuff i just now got to retorquing.
so in closing,
i still believe much care should be taken when torquing with studs, how ever it is much more important to use proper tools.
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should this be stickied? i think it should be stickied, i wish someone would have stickied a thread like this before i took on my headgasket replacement
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You just wrote the damn thread.. GIVE ME TIME MAN! HAHA
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ive always done 10 or 11 lb increments... 22, 33, 44.. 90* twist so on...
but why so much torque? the stock non tty bolts that had were not 100.... and the 11mm block cracks so nice when over heated a couple times.. i cannot see why the risk...
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Mod decided to stickie it someplace else. Showed you who is da boss here.
Interesting, Don't plan to do another head soon but maybe good advice for this sort of torque. Go easy at the end and save parts.
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i went for 100, because the stud paper said 80 ft lbs, but since these are 11mm studs they are made for vw gasser engines, and 12mm diesel engines are rated for 125lbs so i figured i'd meet in the middle, because i certainly didn't want to over tighten on an 11mm, but at the same time i didnt want another head gasket failure. also old threads about people running 11mm threads most were running 110 or more ft lbs
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i went for 100, because the stud paper said 80 ft lbs, but since these are 11mm studs they are made for vw gasser engines, and 12mm diesel engines are rated for 125lbs so i figured i'd meet in the middle, because i certainly didn't want to over tighten on an 11mm, but at the same time i didnt want another head gasket failure. also old threads about people running 11mm threads most were running 110 or more ft lbs
Science like this should never make a sticky.
Did you use the right nuts? did you use the right washers?
What if any lube was used?
What's the thread pitch?
Why are you trying to use 12mm specs in a 11MM motor?
How deep is the dent in the top of your head from the one you overtightened?
Never bottom the stud out.
Torquing is more accurate in one single motion.
Did you hang the corner of the exhaust manifold up on the block by any chance?
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Science like this should never make a sticky.
Did you use the right nuts? did you use the right washers?
What if any lube was used?
What's the thread pitch?
Why are you trying to use 12mm specs in a 11MM motor?
How deep is the dent in the top of your head from the one you overtightened?
Never bottom the stud out.
Torquing is more accurate in one single motion.
Did you hang the corner of the exhaust manifold up on the block by any chance?
woah woah. this is a warning for those running 12mm studs as well, because like i said the same thing happened to andy, and he was following the directions directly
so to answer your questions, i followed the directs to a t, other than torque numbers( which it is not very specifici about other than the final number)
yes i used the supplied washers, yes i used the supplied ARP lube, which was put on all the threads and the bottom contact surface of every nut. i have no idea what the thread pitch is, i did no use 12mm torque specs on the 11mm studs, i used lower specs than the 12mm, and lower specs than i could find anyone using on an 11mm diesel by search vwdiesel.net on the topic of studs. never bottom out the stud? i hand tightened them as the instructions say. did not hang the corner of the exhaust manifold.
to be clear also, i didn't feel attacked by what u said, those are totally legit questions that you asked, im just discussing this stuff. just wanted to make there wasnt a tone added to what im writing. im totally open minded i just want to help keep people from being in the same shoes as me and andy.
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my only reason id run a stud is the rumor they sit further in the block...
whats a 11mm diesel torque spec?? why would this convert a 11mm into a 12mm setting?
ive had lot say this no work.. but i see it and tested it.. using the 11mm tty later 1.8-2.0 headbolts torqued to gasser specs with no issue...
but the 1 thing i know for fact.. over heat a 11mm block 1 time to many.. next head gasket may kill it... done quite a few in the day... that crack/snap is like breaking the injector boss off the head.. just sick feeling... so no way id ever try what you did... headgasket cheaper then bottom end...
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woah woah. this is a warning for those running 12mm studs as well, because like i said the same thing happened to andy, and he was following the directions directly
so to answer your questions, i followed the directs to a t, other than torque numbers( which it is not very specifici about other than the final number)
yes i used the supplied washers, yes i used the supplied ARP lube, which was put on all the threads and the bottom contact surface of every nut. i have no idea what the thread pitch is, i did no use 12mm torque specs on the 11mm studs, i used lower specs than the 12mm, and lower specs than i could find anyone using on an 11mm diesel by search vwdiesel.net on the topic of studs. never bottom out the stud? i hand tightened them as the instructions say. did not hang the corner of the exhaust manifold.
to be clear also, i didn't feel attacked by what u said, those are totally legit questions that you asked, im just discussing this stuff. just wanted to make there wasnt a tone added to what im writing. im totally open minded i just want to help keep people from being in the same shoes as me and andy.
Supplied washers may not be right for the application, especcally if you are ordering from another part of the catalog. I know one guy who caved in the aluminum around the head bolts, because the company he got his ARP bolts from found some with threads that fit, and include the washers to match...and i'm sure those washers were just fine on an iron head.
IIRC ARP claims there lube to reduce the needed torque 20-30 %, so it's like you went to ~130lb
Some studs like my Raceware are fine pitch at the nut end, offering greater strength, and about double the clamping force at a given torque. Added to special lube, that would be like cranking the regular bolt down to 260lb!
The only thing bottoming a stud accomplishes is to apply a jacking force against the threads of the block, and to insure it is stuck if it breaks. Better practice to keep them 1/4 turn out.
Gasket crush should be less than 0.7MM, that is some turn on a nut, but not much.
was the nut that went bad at the bottom of the threads on the stud?
I can't help but think something wasn't right.
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Being the Head stud advocate for 11mm blocks that I am I'm gonna open my big fat mouth.. ARP (like everything else) ain't what it used to be.. In the last year I've had three out of five ARP fastener sets come with issues.. Two of them (main studs for a GM 5.7 Diesel and Rod bolts for a VW 1.6 Diesel) had the threads botched when they cut them.. The other (pan and timing cover studs for a GM LT1 5.7) came with the wrong damned nuts.. As far as past sets from years back, installed as per their specs and never an issue...
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Gasket crush should be less than 0.7MM, that is some turn on a nut, but not much.
I don't know what the pitch is on the ARP studs, but that has to be at least 1/2 a turn.
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studs were just run into the block till they stopped turning using just an allan socket on the end of 3/8 extension, maybe it is best to undo them a quarter, but hand tight is what the instructions say.
ok looking at things more, the nut threads are finer than the block threads.
the washers definitely appropriate, they looked like the ones i had removed, and fit very tight down in the hole in the head and also tightly around the stud.
the stud threads look mostly ok but the nut threads are squared off looking.
i was going for 100 ft lbs because i had read from searching the forums many people running that number, or higher on 11 and 12mm studs both.
i just wanted to warn everyone that you should definitely step more slowly at higher numbers as this same thing happened to andy as well, and he was following the directions to a T.
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at 100, the trouble started!!!!!!!!!!!!!!!!!!!!!!!!!! the first stud was difficult how ever not impossible to turn, and i got it up to 100 ft lbs. the second stud how ever would not budge. i'll be honest, i have always been a scrawny guy, but seriously this one would not move, it ended up feeling like i was going to strip the 12pt shape of the nut so i
stopped. and i was like well i'll skip that one, and i did 3-4-5-6, then went back to 2, and that nut wouldn't budge, i ended up half stripping off the 12 pt shape. so since that wasn't going well, i removed the nut and stud, the nut was very difficult to get off the stud, and when i looked inside the nut, all the threads were squared off.(
What do you mean it wouldn't budge?
Weren't you using a torque wrench set to 100 ft lbs?
Did the torque wrench click?
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at 100, the trouble started!!!!!!!!!!!!!!!!!!!!!!!!!! the first stud was difficult how ever not impossible to turn, and i got it up to 100 ft lbs. the second stud how ever would not budge. i'll be honest, i have always been a scrawny guy, but seriously this one would not move, it ended up feeling like i was going to strip the 12pt shape of the nut so i
stopped. and i was like well i'll skip that one, and i did 3-4-5-6, then went back to 2, and that nut wouldn't budge, i ended up half stripping off the 12 pt shape. so since that wasn't going well, i removed the nut and stud, the nut was very difficult to get off the stud, and when i looked inside the nut, all the threads were squared off.(
What do you mean it wouldn't budge?
Weren't you using a torque wrench set to 100 ft lbs?
Did the torque wrench click?
good question, it simply wouldn't turn, and no the torque wrench wasn't clicking, im guess this is because the 12 point shape was beginning to strip rather than the nut spinning?
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at 100, the trouble started!!!!!!!!!!!!!!!!!!!!!!!!!! the first stud was difficult how ever not impossible to turn, and i got it up to 100 ft lbs. the second stud how ever would not budge. i'll be honest, i have always been a scrawny guy, but seriously this one would not move, it ended up feeling like i was going to strip the 12pt shape of the nut so i
stopped. and i was like well i'll skip that one, and i did 3-4-5-6, then went back to 2, and that nut wouldn't budge, i ended up half stripping off the 12 pt shape. so since that wasn't going well, i removed the nut and stud, the nut was very difficult to get off the stud, and when i looked inside the nut, all the threads were squared off.(
What do you mean it wouldn't budge?
Weren't you using a torque wrench set to 100 ft lbs?
Did the torque wrench click?
good question, it simply wouldn't turn, and no the torque wrench wasn't clicking, im guess this is because the 12 point shape was beginning to strip rather than the nut spinning?
Did you have to correct size 12 point socket?
Is your torque wrench in calibration and good working order?
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Yes correct socket and have never had an issue with this wrench, also tightened other nuts directly afterwards with out issue
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ok looking at things more, the nut threads are finer than the block threads.
Well there is a problem
Mine are at 55 ft/lb, with a warning NOT to use any special slippy lube.
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The instructions with the studs said to go to 80ft lbs and to use the arp lube. And actually the nut i had issue with was never torqued over 70 ft lbs since it didnt even move when i went to give it 100
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I'll chime in here: My original set of head studs were not ARP. They were from a company called Raceware Engineering. Mine were not supplied with assembly lube, and the instructions said to instead use straight weight motor oil. Mine were only to be torqued to around 50 ft-lbs. Still, I suffered the same failure of RJ, on the same bolt.
745, why is torquing more accurate in one single motion? I always thought torque was torque, regardless of how many steps it takes to get to final spec, and slow-stepping to final spec looks to reduce the localized stress to the head caused by large torque values at higher steps. Your thoughts?
Note: On the ARP stud set, my torque application was in 3 roughly equal steps, 45-85-125. I had no faults, and none of the areas under the washers are caved in. Directions were, quote: "Torque nuts using ARP lube in 3 equal steps to 125 ft-lbs."
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I think a lot of companies that were once thought of as good stuff now are suffering the deals I have seen elsewhere in the fastener industry. These American companies are getting sub par steel. It used to be the American companies would have American melt and American machined stuff, then there was Canadian melt and American machined, which was still good. Now the alloys are globally sourced and you can see the results speak for themselves. Nucor and Holochrome are the only all American melt and machined products that I have found to sell. Sadly they are more for the industrial side of things, and do not offer studs for our engines. Another rumor I have heard and have no clue if it is accurate or not is that ARP gets the 2nd batch or the rejected melts that our US gov. turns down for the military. Just speculation and rumor but I could see it is possible.
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745, why is torquing more accurate in one single motion?
I would think torque is torque as long as the bolt/nut is moving when it reaches the desired torque value.
EX: If you are using a ratcheting, clicker torque wrench and you are tightening a nut but run out of room and have to bring the wrench CCW to get more room and the wrench instantly clicks before the nut moves, the nut is under-torqued.
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Exactly, breakaway torque starts you moving. Once moving, you have thread friction, face friction friction, and clamping force. You guess at the two trying to land the 3rd where you want it....makes TTy sound like a good idea :-X. Also probably why every torque to angle spec says ,'in one smooth motion'
My Racewares have been in there 4-5 years i think.
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Also probably why every torque to angle spec says ,'in one smooth motion' Double up on that!
Why do you think the Bentley tells us to loosen the bolts back about 30 degrees then bring them back to torque spec. It is for the reasons stated prior. The breakaway may be more than the clamping and thus you need to get rid of that force to accurately get to the proper clampping one.
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at 100, the trouble started!!!!!!!!!!!!!!!!!!!!!!!!!! the first stud was difficult how ever not impossible to turn, and i got it up to 100 ft lbs. the second stud how ever would not budge. i'll be honest, i have always been a scrawny guy, but seriously this one would not move, it ended up feeling like i was going to strip the 12pt shape of the nut so i
stopped. and i was like well i'll skip that one, and i did 3-4-5-6, then went back to 2, and that nut wouldn't budge, i ended up half stripping off the 12 pt shape. so since that wasn't going well, i removed the nut and stud, the nut was very difficult to get off the stud, and when i looked inside the nut, all the threads were squared off.(
What do you mean it wouldn't budge?
Weren't you using a torque wrench set to 100 ft lbs?
Did the torque wrench click?
good question, it simply wouldn't turn, and no the torque wrench wasn't clicking, im guess this is because the 12 point shape was beginning to strip rather than the nut spinning?
I am still unclear what was happening.
You said:
1. The torque wrench didn't click.
2. It wouldn't turn. Please clarify what is "it" was, that wouldn't turn
If the "it" was the nut and it wouldn't turn then the torque wrench should have clicked since you are capable of putting out 100 ft lbs?
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torque wrench would not turn with out feeling like it was going to slip off the nut. torqued #1 in sequence to 100 ft lbs, then #2 wouldn't turn felt like it was going to slip off/strip the nut but didn't click, so i skipped it did 3-6 in sequence all to 100 ft lbs, and it did click, went back to #2 still wouldn't turn so i removed it and the threads were all boxy looking.
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Well, the good news is ARP's warranty department kicks ass, I just had a short conversation with them, told them what happened, and they're sending me a new stud, washer, and nut out tomorrow. only crappy part is i have to wait a week before it gets here, atleast it was totally painless to get the new parts tho.
andy how ever says raceware is giving him the run around about warranty on the studs he had the same problem with. just based on that i think i will stick with arp in the future.
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first off, i would like to apologize for all the broken families and aneurisms that this thread which I have created may have caused.
Secondly, i'd like to let you all know that i deeply care about every single one of you.
The depth to which i care, is exactly why i am about to make a sacrifice, that many would shy away from. Many, simply do not have the balls to do what i am prepared to do for this community, whom i care so much about.
I will proudly wear egg on my face for you, vwdiesel.net.
the problem was my very own fault, as the nut tightens over the stud, the stud begins to stick up, i measured them at .240" above the nut at full tightness, and if you are not using a socket that is deep enough then obviously at some point its going to slip. this is why like i said on the stud i had a major issue with, i couldn't tighten it with out it feeling like it was going to strip. I failed to notice this is what was going on until today when i was retorque after warmup. i realize its been about a month and a half since i initially posted this, but between making time to work on it, and a few other problems i had, plus waiting on parts and stuff i just now got to retorquing.
so in closing,
i still believe much care should be taken when torquing with studs, how ever it is much more important to use proper tools.
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Why is it that our second look a month or two later is crystal clear what the problem is and how to fix it? I have in my own frustration put a project away for awhile in order to come back to it with that 20 20 vision and be done in half a day. But it takes several weeks to clear the confusion and be able to look at it anew.
Thanks for admitting to the oversight. We will send the thugs over later to deal with you.
LOL
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the thugs are not necessary, karma already visited me for making thisthread. when i did the hot retorque the block cracked.
i actually replaced the headgasket twice on this car, since i initially made the thread, the first hg i messed up when i installed it causing compression to get in the coolant, so i redid the hg job, and now on my retorque with the second new gasket the block cracked.
so actually, the moral to this thread, is if you're going to do a headgasket on an 11mm engine, dont buy the head gasket or the studs, just throw out the engine and find a 12mm one.
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so actually, the moral to this thread, is if you're going to do a headgasket on an 11mm engine, dont buy the head gasket or the studs, just throw out the engine and find a 12mm one.
It's a sucky lesson to learn but I learned that lesson the same way a few years ago. After that, I gave away the only good 11mm block I had other than the one that is currently running fine in my rabbit. If it ever has an issue with the head gasket, I will pull it and install a 'real' 1.6TD or bigger... Do you have another engine to install?
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I have a couple options but nothing straight forward.
See what i want is just a straight 1.6 that i could put my spearco turbo kit on
But what i have is
A 1.6td hydro block just needs put together with new rings and bearings
Then i have 2 aaz heads, which are not of use for this car since i just want a straight 1.6
My dad has a block i could have its a solid lifter 12mm 1.6na block, but were not sure of condition it may need bored out. If the bores ok ill just rering that and sit my 11mm head on it well see.
I thought the studs would keep me safe from cracking but they didnt and it now has turned into a huge waste of time and money. But life goes on
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How does one go about cracking the block when applying the necessary torque to the hot head? Shall I freight you my spare 1.6 block?
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The 11mm blocks crack if you look at them sideways.
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I'm not sure why the 11mm blocks would crack easier than the 12mm.
Bigger hole means less meat between the bolt hole and water jacket,.. unless they changed the casting to provide more meat.
How much did you torque it to?
I use 80ftlbs on my 11mm ARPs, without a problem, so far. Boost spiked to 35 with the incredible back pressure of the VNT, without a problem.
Did you bottom the studs into their holes? They expand at a different rate than the block steel and shouldn't be up against the bottom of the hole.
Which hole cracked out?
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This has probably been asked , is that a fine thread that you are torquing to 80 ft pounds? Cause with the racewares they told me 50 , 60 max. I've never popped a head gasket unless it was my stupidity. I can't imagine the clamp load with 80-100 ft pounds and a fine thread bolt. I'm really suspect of arp's torque values.